package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.collection.CollUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.constant.RedisConstants;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        Long userId = UserHolder.getUser().getId();
        if (isFollow) {
            //1、关注：
            // 新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);
            // 将关注用户的id保存到redis的set集合里面
            if (isSuccess) {
                stringRedisTemplate.opsForSet().add(RedisConstants.RedisFollowConstants.FOLLOWS_KEY_PREFIX + userId,followUserId.toString());
            }
        }else {
            //2、取关
            // 删除数据
            boolean isSuccess = remove(
                    new QueryWrapper<Follow>()
                            .eq("user_id", userId)
                            .eq("follow_user_id", followUserId)
            );
            // 将取关用户的id从redis的set集合移除
            if (isSuccess) {
                stringRedisTemplate.opsForSet().remove(RedisConstants.RedisFollowConstants.FOLLOWS_KEY_PREFIX + userId,followUserId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        Long userId = UserHolder.getUser().getId();
        //查询是否关注
        Integer count = query()
                .eq("user_id", userId)
                .eq("follow_user_id", followUserId)
                .count();
        return Result.ok(count > 0);
    }

    @Override
    public Result followCommon(Long targetUserId) {
        Long currentUserId = UserHolder.getUser().getId();
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(
                RedisConstants.RedisFollowConstants.FOLLOWS_KEY_PREFIX + currentUserId,
                RedisConstants.RedisFollowConstants.FOLLOWS_KEY_PREFIX + targetUserId
        );
        List<Long> userIds = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        if(CollUtil.isEmpty(userIds)){
            return Result.ok(Collections.emptyList());
        }
        List<User> userList = userService.listByIds(userIds);
        List<UserDTO> userDTOList = userList.stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(userDTOList);
    }
}
